Hydrostatic fuse



G. O. ROCKWELL HYDROSTATIC FUSE Dec. 5, 1950 2 Sheets-Sheet 1 Filed Feb. 20, 1946 FIG. 4

, INVENTOR GAY/V0? 0. ROCKWELL ATTORNEY Dec. 5, 1950-. G. o. ROCKWELL V 2,532,645

HYDROSTATIC FUSE FIG. 8

VENTOR 64 man a. nockwau ATTORNEY Patented Dec. 5, 1950 um-ire!) sm'rss PATENT UFFICE "3-Glaims. ((1102- 702) The presentinvention'relates to afu'ze 'for use in -a fluid medium, such as in an underwater ex- 'plo'sive' device operated by the pressure of water at a'predeter'mined depth. 'Moreiparticularly, it

static or equivalent threshold pressure atone predetermined depth, and into which water'or an "equivalent fluid medium forces its 'wayat anotherpressure at'a much greater predetermined blepthto energize asea cell, the output'of which is supplied'to an electric cap orsquibto initiate an explosion.

"E'instingpressure-operated detonators have the disadvantage that they are 'not' operable at great hydrostatic pressures present atde'pths'at 400 to 1,000feet. Existing detonators have thefurther "disadvantagethat they are'not capableof being re-designed to operate at 'hydrostatic'pressures' of ahighorder.

"Itisan object of the present invention to pro- "vide a hydrostatic fuze which will'be operable "at hydrostatic pressures of ahi-gh' order.

'A'further'obje'ct oithe'invention'is to provide ahydrostatic fuze which will be armed by athi'eshold hydrostatic pressure at a predetermined depth and will be subsequently detonatedata i'grea'ter predetermined'tlepth.

Another object of the invention is to provide 1 a? hydrostatic fuze which'is rugged, reliable, "posi- "tive'in action, readily manufacture'd'and which occupies a miniu'm amount of space.

These and other objects of the invention will be better understood'by reference to'thefollowin'g -.d'esc'ription'andaccompanyi'ng drawing, in which Figfl is a perspective view showing the netonator as applied'to'an explosive device;

FigfZ is a perspective view oitheneton'ato'r;

' Fig.3 is a plan View rifthe'lower end'of the 'detonator;

Fig. 4 is a verticalsectionas indicated'by th'e lined- 4 of Fig. 3;

Fig. '5 is an "exploded sectional view "of the rupturing diaphragm assembly; v

Fig. 6 is-a verticalsection asindicate'cl by'th'e 1ine66 of 'Fig."3;

Fig. 7 is aperspective view of the shutter and the shutter release plate;

Fig. 8 is a-vertical section of the shutter as indicated by the line 88 on Fig-7, and

Fig. 9 is'a vertical section of the shutter as indicatedby the line 9-9 of Fig. 7.

Referringto Figs. 1 and 2,-a base 29 carries the working parts o'fthe detonator, represented generall an, and is attachedfto a -body 24 which contains "the main explosive charge.

The working "parts include current generating means using a salt Water electrolyte and known ras adelayed action sea Water-battery, two-rupturing diaphragms, a safety shutter, a shutter release, a shutter-release operating means, a cap,

a tetryl train, a booster-charge, andthe necessary containing and connecting parts.

-Re'fe'rring to FigsI3, and 5, an initially dor- 'rnant sea water battery'EG is contained in a 'ha'niber'ZB in-the baseZB where it is sequestered from the 'eiiternal fluid medium. The seawater battery'Z'S comprises a series of electrode plates "26a which are secured in place by means of a central rod 261) and separatedtherefrom by means of a dielectric washer 'fific. It will be understood "that other forms of sea water batteries may be utilized as current generating means, such as the types disclosed in copending applications, Ser.

No. 476,062 'file'd'by'LewisE.'Kissinger et all, now

{Patent No.2,5'26-,'670, or Ser. No. 711,302 'filed by 'F. F. -Farnsworth, et a1. by a threaded ,pluglifl whichbears on a washer 32 and is furnished with spanner sockets 'fl. Two

The chamber is closed fluid passages "35 'leading from the chamber to the sides ofthebase are closedby the rupturing diaphragm assemblies shown in detail in Fig.6. Thediaphragm assembly consists of a resilient washer 38, a thick metal disk 40 having a central hole "42 with sharp edges, a thin metal disk lid,

whichaidsin the sequestration of the battery, another resilient washer 4'6, and a threaded plug 48. The threaded plug has spanner sockets'fiil.

Ahole52 paralle1 to the flat surfaces of the plug intersects the spanner sockets and an axial hole 54 in the underside of theplug.

One terminal of the sea cell is connected through a hermetically sealed terminal "55 'to a contact 58 carried on the upper surfaceof the base by an insulating striped, the other terminal (not shown) is grounded to the metal of thebase.

Referring now to Fig.6, the base 20 also sup- .ports the shutter-release opera-ting mechanism.

This consistsof a tubular metal bellows -62, fastened at its outer end to the outer end of a tube 64 which passes through the 'base. The inner end of thebellows is secured to a plunger 66 plungers ll-fastened tothe shutter releaseplate {project down into holes "16in the base through threadedplugs l8. -Springs'80fbearing against the undersidesof theplugs and against shouldersilZ-on the plungers, resist upward movement of the shutter-release mechanism.

Referring againto -Fig. 4,. thebase-2D is surmounted by-a shutter housing 84 and a booster carrier plateBfS. These, togetherwith the base,

3 form a space in which a slide member or shutter 88 is laterally slidable. The booster carrier plate has a threaded hole on its upper surface into which a booster charge contained in a cup 9% can be screwed.

Referring now to Figsfli, 8, and 9, the shutter 38 is rectangular in shape with a longitudinal groove 92 in its front face. An opening 9% in the lower side of the groove engages a projection or detent 96 on the edge of the shutter release plate '52 which operates as a detent to hold the shutter in the safe position.

Spring-operated plungers 93 in one end of the shutter move it laterally when it is released, and a similar plunger we in the back face enters a hole 1&2 in the shutter housing 3 (Fig. 4) to lock it in the armed position.

The shutter has a cavity Hi l in the lower surface closed by an insulating cover plate I06. Mounted in holes opening upward from this cavity are a cap or squib 108, a contact pin H and two terminal screws H2, only one of which is shown. The cap W8 is so located that,.when the shutter is in the armed position, it is aligned with a tetryl train in a hole H4 in the booster carrier plate 86 as shown in Fig. 4. The contact pin H0 projects through a hole in the cover plate I06. It is mounted, with its driving spring H6, in a tubular holder H8 which, in turn, is held in an insulating cup I20. The terminal screws H2 are provided to eliminate the necessity of soldering the leads to the cap 38 with the attendant hazard of a possible explosion from the heat. One of these screws is mounted in the shutter in an insulating bushing I22 and provides a means for joining one of the cap leads to the lead from the contact pin. The other screw is used to ground the other cap lead.

The shutter is prevented from moving under the influence of the spring of the locking pin Hill by the shutter release plate 12 and a stop bar 124 attached to the booster carrier plate 86.

In operation, water enters the bellows 62 (Fig. 6), around the rod 68 and, as the device sinks and the pressure increases, tends to expand the bellows and force the shutter release plate 72 upward. The springs 80 are gradually compressed under the effect of the increasing pressure and finally permit the plate to rise high enough for the projection 96 (Fig. '7) to clear the opening 94 in the shutter. The plungers 98 can then force the shutter to move laterally, aligning the cap [08 with the tetryl train in hole H4 and bringing the contact, pin H0 onto the contact 58, thereby arming the detonator. This happens at a depth dependent on the strength of the springs 80.

At the same time water enters the portion of the rupturing diaphragm assemblies external to the thin disks 44 by way of the spanner sockets 5E! and the communicating passages 52 and 54 (Figs. 4 and 6). Pressure is exerted on the thin disks d4 tending to shear them on the sharp edges of the holes 42 in the disks 40. At some depth greater than that at which the arming action takes place, the pressure against the disks is great enough to shear one of them, admitting water to the sea-cell cavity 28. When the plates of the sea cell 26 are contacted by sea water, they produce a voltage which causes a current to flow through the cap Hi8 by way of the hermetically sealed terminal 58, the contact 58, the contact pin H0 and the wiring in the shutter, with the return circuit formed of the metal of the device. The cap explodes, setting oil in turn i the tetryl train m, the booster which detm nates the main charge 24.

I claim:

1. In a hydrostatic fuze including an electrically detonatable squib and a delayed action sea water battery having an entry port normally closed by a diaphragm capable of being fractured at a predetermined pressure for permitting the entry of sea water for activating the battery, means for connecting said battery to said squib comprising a slidable connecting member having an armed and an unarmed position, resilient means urging said member toward said armed position, detent means normally retaining said connecting member in the unarmed position, and fluid pressure operated means including a bellows expansible by a predetermined fluid pressure of a different force than said first-mentioned pressure for moving said detent to release said connecting member for movement to its armed position.

2. A hydrostatic fuze including an electrically detonatable squib and a delayed action sea water battery having an entry port normally closed by a diaphragm capable of being fractured at a predetermined pressure for permitting the entry of sea water for activating the battery, in combination, a slidable connecting member having an armed and an unarmed position, said member having a groove and a communicating opening, resilient means urging said member toward said armed position, detent means operable beside said member and having a projection occupying the opening to detain said member in the unarmed position, and spring-loaded fluid-pressure operated means coupled to said detent means, being operable by a fluid pressure difierent from the predetermined pressure aforesaid, for moving said detent means counter to its spring loading and in respect to said connecting member to displace the projection into the groove.

3. A hydrostatic fuze having a base including a chamber with a passage potentially open to water access and a bellows open to water entry,

u a dormant battery situated in the chamber and a rupturable diaphragm fixed across the passage to exclude the water until a rupturing pressure is imposed thereon, a spring-loaded member carrying a squib detonatable by activation of the battery, said squib and battery being situated in a normally open circuit, interengaging components forming detent means initially holding said member in an unarmed and circuit-opening position, and a plunger and plate assembly, the plate of which has one of the detent components, the plunger of said assembly being operative by expansion of the bellows to displace the detent means for release of said member to the armed and circuit-closing position.

GAYNOR. 0-. ROCKWELL.

nEFnRnNeEs CITED The following references are of record in the file of this patent: 

